Kiln



ug. T930.

H. M. ROBERTSON KILN Filed Mal;r 9. 1928 3 Sheets-Sheet 1 WHMMM.

fuit/- Aug. 12, 1930. H. M. RoBERTsoN KILN 3 Sheets-Sheet 2 Filed Ma;\r9, 1928 fr G. 5. 40

'f1.2 fr,

v .m Y eigenaars :un

31a/vanto@ 5m@ @my abkomwq Au@ l2, 1930. H. M. ROBERTSON 1,773,011

KILN

s sheets-sheet zs Filed May 9, 1928 Patented Aug. 12, 1930 Parar cariesHARRY M. ROBERTSON, OF CLEVELAND, OHIO KILN Application led May 9, 1928.

This invention relates to a kiln of the continuous type for heattreating or burning various kinds of ware or products. ln theillustrated application of the invention l have shown a kiln of thistype adapted for burning ceramic products', more particularly where thesame are glazed, but the invention in its broaderv sense maybe appliedto the treating of other products as well as ceramic products notrequiring glazing.

One object of the invention is to construct a continuous kiln in which adraft inducing means is connected therewith at or beyond the dischargeend of the heating chamber, whereby air and hot gases are caused to flowthrough the kiln in the same direction as the ware or products move.

Another object of the invention is to construct a continuous kiln inwhich a draft inducing means is connected therewith at or bethe draftinducing means, flows through the kiln in the same direction as theproducts or ware move.

Another object of the invention is to provide in a continuous kilnhaving a preheating chamber, a firing or heating chamber and a coolingchamber, means at the inner end of the cooling` chamber for drawingheated air therefrom, and a separate suction means inwardly of the airdrawing oif means to induce a draft through the preheating and heatingchambers in the direction in which the products move therethrough.

Another object of the invention is to provide an improved continuouskiln capable of rapidly and economically glazing ceramic ware orproducts.

Other objects of the invention will be apparent to those skilled in theart to which my invention relates from the following description takenin connection with the accompanying drawings, wherein Fig. 1 is ahorizontal section showing diagrammatically a kiln embodying myinvention.

Figs. 2, 3, 4, 5, 6, 7 and 8 are sections en- Serial No. 276,306.

larged, on the lines 2 2, 3 3, 4 4, 5 5, 6 6, 7 7, and 8 8 of Fig. 1.

Fig. 9 is a fragmentary vertical section.

Fig. 10 is a section on the line 10-10 of Fig. 3.

In the drawings, 1 indicates a bed formed of suitable material, such asreinforced concrete. The bed is shown more or less diagrammatically, butit may be of any desired construction capable of supporting the kilnstructure.

The kiln comprises vertical side walls 2 reinforced by spaced uprights 3secured at their lower ends in the bed 1 and tied at their upper ends byrods 4. Each wall 2 comprises an inner portion 211 formed of suitablerefractory material, an outer portion 2b and an intermediate portion 2Cformed of suitable insulating material. The inner and outer portions areconstructed of slabs or bricks. 5 indicates caps or base membersextending along the upper ends of the wall portions 2, 2, and supportedthereby and ledges 2b on the inner surface of the wall portion 2b. Thecaps 5 form bases or abutments for the opposite side edges of the roofG, which is preferably arch shaped. The construction of the roof 6 willbe later described. 7 indicates benches eX- tending longitudinally ofthe kiln and forming between them the passage or traversing space forsuitable trucks or carriers A (Fig. 8) which support the products orware. The trucks or carriers may be of any desired construction andarranged to run on tracks 7 (the tracks being omitted from F ig. 1 forsake of clearness). Any suitable means may be provided for moving thecarriers through the kiln and returning them to the inlet end thereof.

The kiln comprises generally a preheating chamber 8 in which watersmoking7 of the products B takes place, a heating chamber 9 in whichoxidizing and vitrifying temperatures are maintained, and a coolingchamber 10, these chambers being in contiguous rela- 9 tion so that theloaded trucks or carriers A may pass successively through them. Thereceiving or outer end of the preheating chamber 8 may have an extendedsection 11, its open end being closed by a door (not shown),and thedischarge end of the cooling chamber 10 may be provided with an eX-tended portion l2, having at its exit a suitable door (not shown). Thesection l2 may also be provided with a supplen'iental cooling means 13,suchas banks of pipes through which air is circulated in any well knownmanner.

The heating of the chamber 9 is effected by combustion of fuel in aplurality of'primary combustion chambers or bones14 formed in each wall2. As shown in Fig. 8, each lire chamber leads inwardly from the cuterside of the wall 2, its inner upper end connecting with a secondarycombustion chamber 15 above and extending longitudinally ofthe adjacentbench 7 Each secondary combustion chamber comprises a rear refractorywall 16, a frontcheckered wall l? 4both eX- tending upwardlyapproximately to the height of the loads B on the carriersA., 8) and atop 18 formed of refractory material and resting on the walls 16 and 17As shown in Fig. 1, I provide in each wall 2 three primary combustionchambers lli (which may be termed the main primary combustion chambers)and also shown in this view I provide a supplemental primary combustionchamberv 19 betweenthe preheating chamber 8 and the heating` chamber 9.In this arrangement of the primary combusv tion chambers the heating ofthe products may be effectively controlled and any one or more may beshut down whenV desired. I have shown the chambers 14 and i9 as adaptedfor burning coal,coke or other form of.

The means 20 may be of any suitable formA to effect burning of salt(sodium chloride) the effect of which is to generate and supply tothetraversing passage the necessary atmosphere for glazing the surfaces ofthe product. The means 2O shown for illustration purposesv comprises acombustion chamber 20iprovidedin one wall 2 or (by prefer-V ence) eachof said walls 2 in opposed relation. Each combustion chamber hereinshown consists of a fire box and a `grate for the combustion of fuel,the salt 'being mixed with the fuel or thrown .on the fire bed insuitable quantities. As the fire boxes or combustion chambers 20 areopen exteriorly of the walls 2, the'salt may be supplied thereto fromtime to time as desired.

Each combustion chamber 20 communi-v cates with the passage for theproducts through an'opening 20, the outer side wall of which is inclinedtoward the traversing passage so that the glazing atmosphere may bereadily collected by the induced draft (to which reference will later bemade) flowing toward the discharge end of the kiln and carried alongtherewith to insure glazing of the products B. The products herein shownconsist of piping formed from clay and are preferably set on end on thecarrier and on each other.

V21 indicates headers disposed opposite each other on the benches 7 at apoint in the traversing passage beyond the opening 20". These headersare formed with chambers 22 into each of which leads a discharge port 23extending` through its inner end wall.V From each of the chambers 22leads a discharge pipe 24 connected at its outer end to an `eirhaustflue 25. The iiues 25 are connected to the inlet port of a suctionmechanism, such as a power driven fan, indicated generally at 26, drivenby a motor 27. The fan 27 serves to set up a draft through the kiln fromits inlet end to the headers 2l and hence causes a `flow of the heatedair discharged into the preheating chamber and the hot gases andproducts of combustion from the econdary combustion chambers throughthis portion of the kiln, as indicated by the arrows in Fig. l.

28 indicates lateral recesses formed in the walls 2 in opposed relationto each other. As shown, the recesses 28are disposed between the .firebox 20 or opening 2Oa and the discharge headers 2l. The recesses 28serve as reservoirs into which the mixed air, gases and glazingatmosphere may expand or circulate to retard their iiow and also changethe direction of their iiow (see arrows in Fig. l) so as to insure acirculation thereof in. around and into the products B being treated.The outer side walls of the recesses 28, that is, the side walls towardthe discharge end of the kiln, are disposed in a converging relation toguide the gaseous products into the traversing passage. y

In the construction herein disclosed I provide means for heating air andconveying such air to the preheating chamber S, into which-it isdischarged, preferably at spaced pointsthroughout its length, forpreheating the products before they ent-er the heating chamber andeffect a removal. of moisture therein; this heating being known waterwith the headers 30 and 32, the pipes of each l series are supportedKA,by spaced piers 33, the

pipes extending through the latter, as shown in Fig. 6. The lower endsof the headers 32 are connected with conduits 34 which in turn areconnected to a main conduit 35 extending transversely of but below thebed l. The conduit 35 leads to a pipe 36, which is connected to theinlet port of a power driven fan or blower 37, which serves to set up asuction and hence draws air through the pipes 3l to the headers 32.V As`willbe understood the products B are heated in the heating chamber torelatively high temperatures according to the'kind of clay used for themanufacture of the products, first to an oxidizing temperature and thento a vitrifyingtemperature whereby the 'silica in the clay on theexposed surfaces of the products is melted so that it may combinechemically with the sodium in the salt, and as the products B passthrough the cooling chamber l0, the heat radiating from the products isutilized to heat the air flowing through the pipes 3l.

3S indicates a motor for driving the fan or blower 3T. 39 indicates anoutlet connected to the outlet port of the fan or blower 37. The outlet39 is connected to a chamber 40 provided on the roof of the coolingchamber l0. rEhe. outlet 39 is provided with a branch 39a which leads tothe atmosphere or is connected to a chimney (not shown). The outlets 39,39, are provided withdampers 4l, 41a, respectively, so that the supplyof heated air to the chamber 40 may be regulated at will. rllhe chamber.40 is formed by the arch wall 6a and side, end and top walls 6b. Theinner side wall 6b is formed with a plurality of ports 6l which registerwith the inlet ends of a plurality of supply conduits 42 formed in andextending longitudinally of the roofs 6 for the heating chamber 9 andpreheating chamber 8. At itsopposite end each conduit 42 is providedwith a branch 42a (see Fig. l0) connected to a header 43 mounted on theadj acent benches 7. 'As will be understood from l, there area pluralityof headers 43 along each bench 7, each thereof being opposite a similarheader on the other bench; the outermost conduits 42y are connected tothe innermost headers 43, the remaining conduits bein respectivelyconnected to the headers in successive order toward the inlet end of thechamber 8. To provide for the conduits 42, each of the roofs 6 for thechambers 8 and 9 consists of an inner arch shaped wall 6c on which areplaced rows of blocks or brick 61 of suitable refractory material, thespaces between the rowsyforming the conduits 42, and an outer archshaped wall 44 of suitable refractory material mounted on the bricks 6and cooperatingwith the wall 6c to complete theconduits .42. To preventloss of heat the roofs 6 may be covered with insulation material 45.Each header 43 is provided with a damper or valve 46 and its inner sidethe roof walls 6C to raise the temperature ofA the air flowing throughthe conduits as wel as to keep it circulating therethrough.

ln my construction of kiln, a draft inducing means is provided at orbeyond the end of the heating chamber and where means are provided forgenerating a glazing atmosphere, the draft inducing means is provided ata point beyond such generating means, the

object being to cause a flow of all gases, including free or suppliedair in the kiln, to flow in the direction in which the products B movetherethrough and to draw from the kiln all of such gases before enteringthe coolchamber l0, so that the products B moving through the latterchamber will be unaffected by the heat of these gases and the airflowing through the pipes 31 may be utilized to absorb heat from theproducts to cool them. By causing the hot gases to flow through the kilnwith the products B they are heated to the desired temperatures in aneconomical manner and at the same time these hot gases are preventedfrom entering the pre heating chamber and heating the products beforethe moisture is evaporated or water smoked therefrom; and by heating airby the heat radiated from the products dueV to cooling thereof andconducting it to the preheating chamber, the products B are heatedsufficiently therein to effect removal of their moisture content beforeentering the heating chamber. f

As the heatrequired for the pre-heating chamber is derived from theheated products, cost of operation is reduced. The temperature of thepreheating chamber is preferably maintained at approximately 300 degreesF. As the products B move through the heating chamber 9 they are heatedto that temperature which will melt the silica in the material ofthesurfaces of the products. The salt which is burned in the fire boX 20 isreduced into its component parts (chlorine and sodium), the chlorinepassing oli" with the hot gases and products through the headers 2l andpipes 25, whereas the sodium vaporized and combines with the silica toform on the surfaces of products B sodium silicate, which constitutesthe glaze thereon.

In my construction of kiln the products to be glazed are moved throughthe successive chambers in batches or charges mounted on carriers A, thelatter being introduced sucdescription herein are purely illustrativeand arenot intended to be in anysense limit- What I claim is.:`

l. In apparatus of the class described, the combination of a preheatingchamber and a heating chamber, said chambers being' `disposed incontiguous relation toy form a passage for product bearing carriers,heating means for said heating chamber, means having connection withsaid passage at a point beyond said heating means and serving toinduceaovv ofthe hot gasesthrou'gh saidk passage in the direction ofmovement of the carriers, and a lateral chamber -tormed in the wall ofsaid passage between' said heatingk means and the connection for saidiow inducing means.

2. In apparatus of the class described, the combination of a preheatingchamber having supply lports anda heating chamber, said chambers beingdisposed in contiguous relation to form a passage for product bearingcarriers, heating means for said heating chamber, means havingconnection With said lpassage at a point beyond said heating means andserving to induce a flow of the hot gases through said passage in thedirection of movement of the carriers and discharging them exteriorly ofsaid chambers, and means for supplyingy heated Watersmoking atmospheretosaid supply ports.

3. In apparatusof the class described, the combination of a preheatingchamber having supply ports and a heating chamber, said chambers beingdisposed in contiguous relation to form a passage-for product bearingcarriers, heating means for said heating chamber, means havingconnection With said passage at a point beyond said heating means vandserving to induce a liovv of the hot gases through said passage in thedirection of movement of the carriers and discharging them eXteriorly ofsaid chambers, means for conveying air through a portion of said passagebeyond said flow inducing means and conducting the heated air to saidsupply ports.

4. In apparatus of the class described, the combination ofa preheatingchamber lhaving supply-ports in spaced relation lonthrough said passagein the direction ofV movement of the carriers, and means for supplyingheated Water smoking atmosphere to4 said supply `ports. r

5. In apparatus of the class described, the combination of a preheatingchamber having a supply port and a heating chamber, said chambers beingdisposed in con tiguous relation to form a passage for product bearingcarriers, heating means for said heating chamber, suction meansconnected with said passage at a point beyond said heating means andarranged to induce a floW of the hot gases through said passage in thedirection of travel of the carriers and to draw hot gases and air mixedtherewith from said passage, a conduit formed in the roof of saidAheating' chamber and extending longitudinally thereof and connectedwith said supply port, and means for supplying 'i air to lsaid conduit.Y

6. In apparatus of the class described, the combination of a preheatingchamber having supply ports disposed in spaced relation longitudinallythereof and a heating chamber, said chambers being disposed incontiguous relation to form a passage for product bearing carriers,heating means for said heating chamber, suction means connected Withsaid passage at a point beyond said heating means and arranged toinducea ow of the hot gases through said passage inthe direction `of travel ofthe carriers and to drawl hot gases and air mixed therewith from saidpassage, conduits formed in the roof of said heating chamber andextending longitudinally thereof and leading to one or more of saidsupply ports, and means for supplying air to each of said conduits. Y

7. In apparatus of the class described, the combination of a preheatingchamber and a heating chamber, said chambers being disposed in.kcontiguous relation to form a passage for productbearing carriers,heating means 4for said heating chamber, suction means having connectionwith said passage at a point beyond said heating means and serving todraw air and hot gases through said passage in the direction of travelof the carriers, and a lateral chamber formed-in the side Wall ofsaidpassage between said suction means vand said heating means and arrangedto retard the flow of air and hot gases through said passage.

8. In apparatus of the class described, the combinationof a preheatingchamber having supply ports disposed in spaced relation 1ongitudinallythereof and a heating chamber,

loo

said chambers beingr disposed in contiguous relation to form a passagefor product bearing carriers, heating means for said heating chamber,suction means connected with said passage at a point beyond said heatingmeans and arranged to draw hot gases and air mixed therewith from saidpassage, conduits forme-c in the roof oi said heating chamber and leadtoone or more of said supply ports, means iior supplying air to each ot'said conduits and a lateral chamber formed in the side wall of saidpassage between said suction means and said heating means and arrangedto retard the iiorv of air and hot gases through said passage.

9. in apparatus of the class described, the combination of a preheatingchamber having a supply port, a heating chamber, a cooling chamber, theroots for said preheating and heating chambers being formed with aconduit connected at its outer end with said supply port, means forheating saidL heating chamber, and an air conduit extendinglongitudinallythrough said cooling chamber ind connected at itsdischarge end With said irst mentioned conduit, said connectionincluding means for causing a flow of the air through said conduits.

l0. ln apparatus of the class described, the combination of a preheatingchamber having a plurality of supply ports spaced longitudinallythereoi, a heating chamber, a cooling chamber, the'roois for saidpreheating and heating chambers being formed With a series ot conduitseach connected at its outer end to one of said ports, means for heatingsaid heating chamber, and a conduit extending through said coolingchamber and connected with said hrs-t mentioned conduits, saidconnection including means for causing a flow ot air through saidseriesof conduits and said air conduit.

ll. In apparatus of the class described, the combination of a preheatingchamber,a heating chamber, said chambers being disposed in contiguousrelation to form apassage for Ware bearing carriers, combustion means incommunication With said passage through said heating chamber formaintaining a vitrifying temperature therein, suction means connected tothe discharge end ot said heating chamber for inducing a flow ot' airand hot gases generated by said combustion means through said chambersin the direction of move nent oit' the products, and means between saidheatingmeans and said suction means for creating a glazing atmosphere.

l2. In apparatus of the class described, the combination of a preheatingchamber, a heating chamber, said chambers being disposed in contiguousrelation to form a passage for product bearing carriers, combustionmeans in communication with said passage for heating the Ware as itmoves through said heating cnamber, means in one Wall of said heatingchamber beyond said heating means for creating a glazing atmosphere, andsuction means connected to said passage beyond said glazing atmospherecreating means for inducing a lionv ot the hot gases through said t geoi said heating chamber and of the a .rnospherc said passage inthedirection in r. i the carriers move. n

lo. in apparatus of the class described, the combination of a preheatingchamber, a heating chamber, said chambers being disposed in contiguousrelation to form a passage for product bearing carriers, combustionmeans in communication with the passage through said heating chamber,means in one Wall of said heating chamber beyond said heating means forcreating a glazing atmosphere, suction means connected to said passagebeyond said glazing atmosphere creating means for inducing a flow of thehot gases and atmosphere in said passage in the directi-on in Which thecarriers move, and alateral chamber in the Wall of said heating chamberdisposed between said suction means and said glazing atmosphere creatingmeans.

le'. ln apparatus of the class described, the combination oi' apreheating chamber, a heating chamber, said chambers being disposed incontiguous relation to form a passage for product bearing carriers,combustion means in communication with the passage through said hea-tingchamber, means in one Wall ofsaid heating chambery beyond said heatingmeans for creating a glazing atmosphere, means for supplying heated airto said preheating chamber and means beyond said glazing atmospherecreating means for drawing the atmosphere from the Ware passage andpreventing flow thereof into passage through said heating chamber. l

l5. ln apparatus of the class described, the combination ot' apreheating chamber, a heating chamber, said chambers being disposed incontiguous relation to form a passage for product bearing carriers,combustion means in communication With the passage hrough said heatingchamber, means in one Wall or said heating chamber beyond said heatingmeans for creating a glazing atmosphere, suction means connected to saidpassage beyond said glazing atmosphere creating means for inducing aflow of the hot gases and atmosphere in said passage in the direction inwhich the carriers move, and means for supplying heated air tosaid'preheating chamber. i

i6. ln apparatus of the class described, the combination of a preheatingchamber, a heating chamber, said chambers being disposed in contiguousrelation-to i'orm a passage for product bearing carriers, combusti-onmeans in communication With the passage through said chamber to causevitritication of the products, means arranged beyond said heatmg meanstor creating' a glazing atmosphere luc in said passage, separate meansfor maintaining a water smoking temperature in said preheating chamber,and means for preventing the hot gases in said heating chamberfr-omflowing into said preheating chamber, and the glazing vatmosphere fromflowing into the heating chamber.

17. In apparatus of the class described, the combination of a preheatingchamber, a heating chamber, said chambers being disposed in contiguousrelation to form a passage for product bearing carriers, means forsupplyingA heat into the passage through said pre-A heating chamber toeffect water smoking of the products while kmoving therethrough,combustion means in communication with the passage through said heatingchamber and maintaining a temperature suiicient to mature the productsas they move through the exit portion of said chamber, and meansarranged beyond the heating means for creating a glazing atmosphere insaid passage.

18. In apparatus of the class described, the combination of a preheatingchamber, a heating chamber, said chambers being disposed in contiguousrelation vto form a passage for product bearing carriers, means forsupplying yheat into the passage through said preheating chamber toeiect water smoking of the products while moving therethrough,combustion means in communication with the passage through said heatingchamber and maintaining a temperature sulicient to mature lthe productsas they move through the exit portion of said chamber, means arrangedbeyond the heating means for creating a glazing atmospherefandmeansconnected with said passage ata point beyond the last mentioned meansfor drawing from said passage the hot gases and atmosphere containedtherein.

In testimony whereof, I have hereunto subscribed my name.

p HARRY M. ROBERTSON.

